When we turn back to the Old Testament of the Bible, we see that after sin entered into the world, God required the blood sacrifice of animals for the atonement of sins.

Leviticus 17:11, For the life of the flesh is in the blood: and I have given it to you upon the altar to make an atonement for your souls: for it is the blood that maketh an atonement for the soul.

Leviticus 4:3-5 If the priest that is anointed do sin...then let him bring for his sin, which he hath sinned, a young bullock without blemish unto the LORD for a sin offering....he shall... lay his hand upon the bullock's head, and kill the bullock before the LORD. And the priest that is anointed shall take of the bullock's blood, and bring it to the tabernacle of the congregation...

But the blood of the animals still couldn't do the trick. The Israelites were still unfaithful to their God as evidenced by their awhoring after other gods. A better sacrifice was needed.

Hebrews 10:4 For it is not possible that the blood of bulls and of goats should take away sins.

God promised His people, the Jewish people, a new covenant about 600 years before the coming of Christ. We will see that this covenant would also require blood.

Jeremiah 31:31 Behold, the days come, saith the LORD, that I will make a new covenant with the house of Israel, and with the house of Judah:

31:34 And they shall teach no more every man his neighbour, and every man his brother, saying, Know the LORD: for they shall all know me, from the least of them unto the greatest of them, saith the LORD: for I will forgive their iniquity, and I will remember their sin no more.

In the Bible, we have the Old Testament (or Hebrew Scriptures) and the New Testament. Both were ushered in by blood. The Old Testament came by the blood of animals. The New Testament by the blood of Jesus Christ.

Old Testament

Exodus 24:8 And Moses took the blood, and sprinkled it on the people, and said, Behold the blood of the covenant, which the LORD hath made with you concerning all these words.

Hebrews 9:18-20 Whereupon neither the first testament was dedicated without blood.
For when Moses had spoken every precept to all the people according to the law, he took the blood of calves and of goats, with water, and scarlet wool, and hyssop, and sprinkled both the book, and all the people,

Saying, This is the blood of the testament which God hath enjoined unto you.

New Testament
Matthew 26:28 For this is my blood of the new testament, which is shed for many for the remission of sins.

--Jesus Christ

The animal sacrifices of the Old Testament were only a picture of the ultimate sacrifice. When Jesus Christ went to the cross almost 2,000 years ago, He was the ULTIMATE sacrifice. A bloody sacrifice indeed.

His skin was whipped off,

His beard was torn out of his cheeks,

His head pierced with thorns,

His face beaten to a pulp. He was unrecognizable. The Bible says He was more marred than ANY man.

His hands and feet were nailed through with thick spikes,

His side pierced with a spear after He died.

The sacrifice of Jesus Christ, the Son of God, completely abolished the system of animal sacrifice forever. The animal sacrifices of the Old Testament were only a picture, a figure, of the true sacrifice of Jesus Christ. Their blood was only a figure of the true blood that would be shed thousands of years later on a cross outside the city of Jeruselem. The animal sacrifices were...

Hebrews 9:9 ...a figure for the time then present, in which were offered both gifts and sacrifices, that could not make him that did the service perfect, as pertaining to the conscience...

9:11 But Christ being come an high priest of good things to come, by a greater and more perfect tabernacle, not made with hands, that is to say, not of this building;

9:12 Neither by the blood of goats and calves, but by his own blood he entered in once into the holy place, having obtained eternal redemption for us.

9:13 For if the blood of bulls and of goats, and the ashes of an heifer sprinkling the unclean, sanctifieth to the purifying of the flesh:

9:14 How much more shall the blood of Christ, who through the eternal Spirit offered himself without spot to God, purge your conscience from dead works to serve the living God?

The blood of animals had to be shed over and over but the blood of Jesus was shed only one time. The Catholic religion does not understand this and contends that the blood is shed over and over again in the mass, but the Bible says something different:

Hebrews 10:12, ...after he had offered one sacrifice for sins for ever, sat down on the right hand of God.

Hebrews 7:27 ...this he did once, when he offered up himself.

Hebrews 9:28 ...Christ was once offered to bear the sins of many...

Hebrews 10:10 By the which will we are sanctified through the offering of the body of Jesus Christ once for all.

Hebrews 10:14 For by one offering he hath perfected for ever them that are sanctified.